将mat从DLL c++传递到图像资源c#

我正在使用Visual c# 2010，我喜欢从DLL c++发送图像到我的Visual c# 2010。图像有166*166*24从DLL c++发送到c#。我使用以下代码:

main.cpp

unsigned char*   test()
        {
read image from filename
        Mat OriginalImg = imread(fileName, CV_LOAD_IMAGE_COLOR); 
         return (OriginalImg.data);} 
  OriginalImg.data return the pointer to the image.

main.h

 extern "C" { __declspec(dllexport) unsigned char* test();}

，在我的visualc#程序中，我使用以下代码:

 [DllImport("testng.dll", CallingConvention = CallingConvention.Cdecl)]
               private static extern IntPtr test();
        IntPtr intPtr1;
                    BitmapImage bitmapImage;
        calling the c++ dll
                    intPtr1 = test(1);
                    if (intPtr1.ToString().CompareTo("0") != 0)         
                    {     
create a bitmap with the pointer         
                    Bitmap bitmap = new Bitmap(166, 166, 3 * 166, System.Drawing.Imaging.PixelFormat.Format24bppRgb, intPtr1);
to show the bitmap i need to convert it to a bitmap image
                    bitmapImage=convertBitmapToBitmapImage(bitmap); 
                    System.Windows.Media.ImageBrush ib = new System.Windows.Media.ImageBrush();
                    ib.ImageSource = bitmapImage;
i put the image received from c++ dll like a background to my canvas: canvasImage
                    windows.canvasImage.Background = ib;
                    }
         BitmapImage convertBitmapToBitmapImage(Bitmap bitmap)
                {
                   IntPtr hBitmap = bitmap.GetHbitmap();
                   BitmapSource retval;
                     try
                        {
                             retval = Imaging.CreateBitmapSourceFromHBitmap(
                             hBitmap,
                             IntPtr.Zero,
                             Int32Rect.Empty,
                             BitmapSizeOptions.FromEmptyOptions());
                        }
                    finally
                       {
                           //DeleteObject(hBitmap);
                        }
                     return (BitmapImage)retval;

                }